Kleptoparasites are fond of theft. While many can forage or hunt on their own, they prefer saving time and effort by stealing. Kleptoparasitism may be of others in the same species (intraspecific) or of another species (interspecific).
Interspecific parasites are commonly close relatives of the organisms they parasitize; a phenomenon known as Emery’s Rule, after Carlo Emery, who made the observation about insects in 1909.
Oystercatchers are a group of waders found on sea coasts around the world. They are fond of mussels and have the unusual ability to crack open bivalve shells. Juvenile oystercatchers readily nip food from adults, as they are not yet strong or skilled enough to open mollusk shells themselves.
A good-looking nest is critical to a chinstrap penguin male in securing a mate. There are always more than a few in a penguin breeding colony that pilfer rocks and other nest materials from neighbors.
Seagulls are noted for aggressive opportunism. They happily snatch the retrievals of diving birds, as gulls are unable to fetch fish from the sea floor themselves.
Freeloader flies visit spider webs, where they scavenge half-eaten stink bugs. Blow flies in the Bengalia genus lurk near ant-foraging trails and steal food and pupae portaged by ants.
Cuckoo bees and cuckoo wasps lay their eggs in the nests of other bees and wasps respectively. Cuckoo hatchlings dine on the food provided for the larvae of the host. This kleptoparasitism differs from brood parasitism, which involves parental care of offspring.